Continuation of this long term program on diverse aspects of the chemical physiology of mammalian male reproductive tracts will include further studies in the following areas: (1) The primary and secondary structures, as well as the biosynthesis and functions, of a unique testis-specific acid-soluble basic protein; (2) Developmental aspects of the presence and functions of iso-accepting species of arginyl transfer RNA molecules in testis; (3) The chemical nature and translation of specific testicular mRNA molecules; (4) Enzymic addition of polyadenylate chains to pre-existing ribonucleic acids in male reproductive organis; (5) Specific histones in the developing testis; (6) Enzymology and regulation of aliphatic polyamine biosynthesis and degradation in male genital organs and their secretions; (7) Enzymes and bulk proteins involved in the post-ejeculatory coagulation of seminal plasma.